This disclosure relates to commercial and residential lighting, and in particular to lighting fixtures designed for screw-in type bulbs, and more particularly to the base of a light-emitting diode (LED) light source intended for use in existing fixtures designed for screw-in type bulbs.
There are millions of existing lighting fixtures originally designed to use incandescent bulbs with the screw-in bases (known to the industry as Edison bases, one example is Edison E26). In recent years compact fluorescent lamps (CFLs) have emerged as a replacement for the much less-efficient incandescent bulbs. Now LED lighting is as efficient as the CFLs, with vastly longer lifetime and without toxic components. One problem with LEDs as replacements for traditional light bulbs and CFLs is that LEDs emit light in a directional manner instead of in all directions.
But there are particular applications that minimize the disadvantage of LEDs noted above. One such application is in wall sconce lights, which do not require the lighting source to radiate light in all directions. The lighting is needed in one direction, radiating away from the wall, with reflection from the diffusing lens or shade sufficient to provide backlighting for appearance. In such an application, not as many total Lumens of light are required because much less light is wasted. Accordingly, less light output means less energy is required and less heat is generated, simplifying the problem of thermal management. This light can be provided by mounting LEDs on only one side of a heat sink structure.
There remains a problem with designing a directional LED light device to serve as a screw-in replacement for incandescent bulbs or CFLs. A bulb is typically screwed into a socket until it makes electrical contact and is hand-tight. A directional LED-based replacement with LEDs mounted on one side may be pointed at a non-ideal angle with respect to where the light is needed when fully screwed into the socket. It may be possible to turn the device counterclockwise somewhat to aim it correctly but that will loosen the device in the socket and may diminish or even break the electrical connection. This condition could either cause the light to go out, or result in a poor electrical connection that gets hot and creates a fire hazard.
The present invention is a bulb base that has a movable or flexible center contact, enabling the LED bulb to screw into a common screw-type socket while making good electrical contact and aiming the light where it is needed. Another embodiment of the invention is a base that screws all the way into any common screw-type socket, then allows the attached LED device to be rotated on the base so the light source can be aimed in the desired direction.
In U.S. Pat. No. 7,296,913, Catalano discloses an LED device that has a separate screw type base intended to screw in to a conventional light bulb socket. Wires then conduct the electrical power to the LED device, which is mounted independently of the base and socket. This differs from the present invention because it does not physically support the LED device in the socket.